1. Field of the Invention
The present invention relates to an exposure apparatus, and more particularly, it pertains to an apparatus wherein a plurality of light emitting devices are arranged at predetermined intervals in a primary scanning direction to form a device row and a plurality of the device rows are arranged in a secondary scanning direction.
2. Description of the Related Art
An organic electroluminescence device incorporating fluorescent organic substances in a light emitting layer, which is referred to as an organic electroluminescence (EL) device, is easier to make than other types of light emitting devices, and can be formed into thin, light weight structures. In view of such advantages, such light emitting devices have been researched and developed as devices for thin display panels. Further, since high performance organic EL devices have recently been obtained, which rival light emitting diodes (LED) in terms of emission luminance, light emission efficiency, durability, and the like, research has been undertaken to apply such devices in exposure apparatuses for exposing photoreceptors such as silver halide photoreceptors.
An exposure apparatus using organic electroluminescence (EL) devices comprises, as shown in FIG. 8, for example, plural sets (two sets in FIG. 8) of device rows arranged in a secondary scanning direction, wherein each set of device rows include light emitting sections 80 emitting light in red (R), green (G) and blue (B) colors which are arranged on a color basis in a primary scanning direction. In FIG. 8, the light emitting sections are indicated by the reference numeral 80 with alphabet suffix R, G or B added for color distinction. However, in this type of exposure apparatus, variation in light quantity among the respective devices causes streak unevenness in the secondary scanning direction in images formed.
In order to solve the above drawback, Japanese Patent Laid-Open Publication (JP-A) No. 2001-356422 has proposed a technique for eliminating such streak unevenness by arranging plural device rows in a secondary scanning direction and repeatedly exposing (multiple exposing) one primary scanning line by use of plural device rows so that variations in light quantity among the devices may be averaged.
However, with conventional multiple exposure apparatuses, there is a problem that exposure position in a secondary scanning direction becomes misaligned, resulting in decreased resolution, despite the multiple exposure of one primary scanning line by use of plural device rows arranged in the secondary scanning direction.